The present invention relates to a method for manufacturing tubular items having a closed end, such as hosiery items or the like, with a single-cylinder circular machine.
Hosiery items are currently manufactured by means of circular hosiery-making machines which form the item usually starting from the upper end of the leg and ending the manufacturing process at the toe, leaving said toe open.
The hosiery items must therefore be subjected to a subsequent sewing or looping operation to close the toe in order to form the finished product.
In view of the fact that the toe closure operation significantly affects the production cost of hosiery items, in recent years methods have been proposed, and machines have been studied, which are meant to manufacture hosiery items with a closed toe, i.e., which obtain, at the output of the circular machine that manufactures them, hosiery items in which the toe is already closed.
The methods proposed so far, however, are unable to obtain a hosiery item with a closed toe which has a degree of finish and/or a production quality which is comparable with that which can be obtained with the conventional looping operation.
The processes that have been tested have clearly pointed out the problem of a considerable increase in the production times of hosiery items or in any case a time increase which makes it economically disadvantageous to manufacture them.
U.S. Pat. No. 5,727,400 discloses a method for producing closed toe hosiery with a single-cylinder circular knitting machine which has a fold-over half-platen carrying radially sliding thread engagement elements. The method includes rotating the knitting machine cylinder about the cylinder axis with 180 degree oscillations to pass a first half of the needle cylinder and the half-platen arranged thereabove in front of a thread feed, whereupon the fed thread is supported upon extracted hook ends of the thread engagement elements, and engaging the supported thread with selected needles of the cylinder for each oscillation. The thread engagement elements are then retracted into the half-platen while retaining the thread or threads supported thereon, and heel knitting takes place with the needles of the first half of the needle cylinder. The half-platen is then folded over so as to face a second half of the needle cylinder to whose needles the thread or threads retained by the engagement elements of the half-platen are passed in the toe-closing operation, whereupon subsequently the remaining portion of the hosiery is knit. While this method for producing closed toe hosiery performs admirably, there is still the need to provide improvements in the toe-closing operation of a tubular knit item.